International Journal of Engineering Science Invention (IJESI) ISSN (Online): 2319 – 6734, ISSN (Print): 2319 – 6726 www.ijesi.org ||Volume 7 Issue 8 Ver IV || Aug 2018 || PP 01-15 Deciphering groundwater quality for drinking and irrigation in rural areas of Paramakudi block, Tamil Nadu Dr. K.Ramesh1, R.M. Balakumaran2 1,2(Centre for Water Resources, Department of Civil Engineering, Anna University, Chennai- 25, India) Corresponding Author: Dr.K.Ramesh Abstract: The groundwater quality of Paramakudi block in Tamil Nadu, was assessed for drinking and irrigation water use. Totally, 17 groundwater samples were collected randomly from bore wells and hand pumps. The physical parameters pH, EC have been determined in the field itself and major ions were analyzed in laboratory. There are various water quality parameters such as TH, scholler diagram, piper diagram, index of base exchange, Gibb’s diagram, chloro-alkaline indices, corrosivity ratio USSL diagram, ilcox diagram, RSC, permeability index, , to know the suitability of groundwater for irrigation purposes. Based on the analytical results, groundwater in the area is generally moderately hard to very hard, brackish, high to very high saline and alkaline in nature. The erratic behaviors of groundwater geochemical elements were spatially given through GIS study. Sodium ion is the most dominant cations and chloride ion as the dominant anions. Assessment of water samples from various methods indicated that groundwater is chemically unsuitable for drinking and irrigation uses in few areas. In general, groundwater in the study area is influenced by both natural and anthropogenic activities. Keywords – Groundwater, spatial variation, domestic, irrigation, ramnad . ----------------------------------------------------------------------------------------------------------------------------- ---------- Date of Submission: 09-08-2018 Date of acceptance: 23-08-2018 ----------------------------------------------------------------------------------------------------------------------------- ---------- I. Introduction Water is essential to all forms of life and makes up 50-97% of the weight of all plants and animals and about 70% of human body. Water is an essential natural resource and an absolute necessity for sustenance of life. Water is not only the most important essential constituent of all human being, animals, plants and other organisms, but it is also pivotal for the survivability of the mankind in the biosphere. Most of the surface waters in India, including both rivers and lakes are getting increasingly polluted due to onslaught of human activities of diverse nature. The demand for water has increased over the years and this has led to water scarcity in many parts of the world. India is heading towards a freshwater crisis mainly due to improper management of water resources and environmental crisis is already evident in many parts of India. Water supply and scarcity has received increasing attention primarily driven by alarming World Health Organization report that 1.1 billion people lack access to safe and affordable water for their domestic use. The growing scales of cultural and technological development pose new threats to water quality. The predicted water demand for future is alarming. Groundwater based irrigated agriculture and drinking water supply has increased many folds during the last few decades and sustainable development of groundwater resources has become the most important in groundwater management. Groundwater is the primary source of water for human consumption as well as for agricultural and industrial uses in many regions all over the world. Due to inadequate availability of surface water, groundwater remains the requirement for human activities. Groundwater remains the only option to supplement the ever increasing demand of water. It is estimated that approximately one-third of the world’s population use groundwater for drinking [1]. It accounts for nearly 80% of the rural domestic water needs and 50% of the urban water needs in the developing countries in India. The quality of the water resources is being increasingly degraded as consequence of its intensified anthropogenic exploitation. In developing countries like India, around 80% diseases are directly related to poor drinking water quality and unhygienic conditions [2]. Groundwater contamination by different pollutants, natural geological formations and due to the intensive agricultural and urban development has placed the whole environment at greater risk. Poor quality of water adversely affects the human health and plant growth. Numerous works have reported in both developed and developing nations that urban development, industrial and agricultural activities directly or indirectly affect groundwater quality [3]. It has been estimated that once pollution enters the subsurface environment, it may remain concealed for many years, becoming dispersed over wide areas of groundwater aquifer and rendering groundwater supplies unsuitable for consumption and other uses. Water quality analysis is one of the most important aspects in groundwater studies. The hydrochemical study reveals quality of water that is suitable for drinking, agriculture and industrial purposes. Groundwater quality monitoring is a tool which provides www.ijesi.org 1 | Page Deciphering groundwater quality for drinking and irrigation in rural areas of Paramakudi block, important information of water management. In this regard, the present work is to discuss the major ion chemistry of groundwater of Paramakudi taluk of Ramnad district and its suitability for drinking and irrigation purposes. II. Study Area The Paramakudi area is located between 9 27’ 39” N and 9 37’ 26” N latitude and 78 21’50” E and 78 37’ 55” E longitude (Figure 1). Paramkudui is the southern part of Tamil Nadu state on East Coast of India. Another name of Paramakudi is also called as Parambai. Parambai that means the Vaigai river cross the town, that means face of the vaigai so called the name. The river vaigai flows through the Paramakudi on its way to the Bay of Bengal. It is located in Ramnad district of Tamil Nadu, India. Paramakudi is the gateway for entrants to Madurai, Sivagangai and Ramnad districts from north and west. The area has a hot tropical climate, the temperature ranges from 22.3ºC to 37.8ºC and the relative humidity is high at 79% on an average and it ranges from 80% to 90% in coastal areas. The northeast monsoon chiefly contributes to the rainfall. Most of the precipitation in the form of cyclonic storms caused due to the depressions in Bay of Bengal. The southwest monsoon rainfall is highly erratic and summer rains are negligible. Agriculture is the main source of livelihood. The main cultivation crops in this area are paddy, millets, chillies, groundnut, gingelly, cotton, pulses, vegetables etc. The soil of the area is covered by deep red, black clayey soil and moderately deep black soil type. Black soil is rich source of calcium, potassium and magnesium, but has poor nitrogen content. The soils are mostly black or black to brownish colour. Alluvial soils occur along the river courses of vaigai. Calcium carbonate concentrations of various sizes and shapes are present in majority of the black soil area and this affects the fertility of the soils. The potash content of soil is high in the area. Groundwater occurs in phreatic aquifer, in generally colourless, odourless and slightly alkaline in nature. Brackish nature of groundwater restricts the use of groundwater for irrigation. III. Methodology A total of 17 groundwater samples were collected from the study area during January 2016 after a detailed well inventory survey. The location of the samples were marked using a handheld global positioning system (GPS). The selected wells are used for domestic and agricultural purposes. The physical parameters pH and Electrical Conductivity (EC) have been determined in the field itself. Cleaned polythene bottles with 1 liter capacity were used as sample containers. After collection, the bottles were sealed, neatly labeled and carried to the laboratory. The chemical analyses were carried out for the major ion concentrations of the groundwater samples collected from different locations using the standard procedures as per standard methods [4]. Chemical constituents such as calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), chloride (Cl-), - 2- - - bicarbonate (HCO3 ), sulphate (SO4 ), nitrate (NO3 ), fluoride (F ) were determined for the groundwater samples. www.ijesi.org 2 | Page Deciphering groundwater quality for drinking and irrigation in rural areas of Paramakudi block, IV. Results and Discussions Groundwater chemistry changes as the water flows along in the underground environment, increasing in dissolved solids and major ions. Generally the groundwater in the study area is colourless, odourless and slightly alkaline nature. To understand the groundwater quality in and around the study area 17 groundwater samples were considered. 4.1 Spatial Variation of General Parameters 4.1.1 Hydrogen ion concentration (pH) The pH of water changes with the production of hydrogen or hydroxyl ion during different chemical reactions. Normally, water pH ranges from 6 to 8.5. It is noticed that water with low pH is tend to be toxic and with high degree of pH it is turned into bitter taste. The pH values of the groundwater samples ranged from 7.6 to 8.6 neutral to alkaline nature. The pH variations (Figure 2) in the study area reflect that groundwater is not highly